1. Field of the Invention
The present invention pertains especially to an optical device and to a lighting and/or signaling system. A preferred application relates to the automobile industry, for vehicle equipment.
2. Description of the Related Art
In the field of optical devices for vehicles, the most conventional techniques consist in carrying out separately the various desired lighting or signaling functions such as: full beam headlight, dipped beam headlight, change-of-direction indicator light or else for example daytime lighting also referred to by its English acronym DRL (Day Running Light).
With the general aim of improving the bulkiness and the visual rendition of luminous systems, there exists in the prior art, optical modules which ally several lighting and/or signaling functions. Thus, document FR-A-2 947 325, which is equivalent to U.S. Patent Publication 2011/0007518, which is incorporated herein by reference and made a part hereof, discloses an optical device furnished with at least two luminous sources each carrying out a function, and with a light guide having a common exit face for the light rays emanating from the two sources. The light guide is common to the two sources, this not being devoid of drawbacks:                either the luminous sources (for example LEDs, light-emitting diodes) are placed side by side facing an entrance face of the guide which is then sheet shaped and the entrance axis of the light guide is placed between the two luminous sources. The overall effectiveness of the device, that is to say the luminous power of the light exiting the guide relative to the luminous power of the light entering the guide, is not optimal. It is also noted that the homogeneity of the illumination on the exit face is not optimal, especially if the light guide is highly arced;                    or a system for coupling the luminous sources is put in place in an upstream part of the path of the rays, which coupling system induces consequent losses in practice. For example, losses by absorption of the order of 50% are frequent for lengths of cylindrical guide serving for coupling of the order of 300 mm.                        